This invention relates to a system for controlling the driving force of a motor vehicle, such as an automobile. More particularly, the invention relates to a system for maintaining motor vehicle driving force by controlling the speed of revolution of a driving wheel to minimize slipping. The system is applicable to automobiles, tractors, motorized bicycles and the like.
The prior art applicable to the present invention includes a driving force control of the type disclosed by Japanese Patent Application (OPI) No. 146755/83. In that application, a driving wheel is controlled by setting its speed of revolution at a value close to a reference speed by comparing the speed of revolution of the driving wheel to the preferred reference speed, and applying braking force when the above comparison reaches a predetermined state.
With respect to this prior art, however, the speed of the driving wheel sometimes may not appear to converge close to the reference speed, because it often is difficult to detect whether the speed of the driving wheel has deviated from the reference speed. If the acceleration of the driving wheel also is measured as a further reference, the problem is overcome. However, the response of the system may be delayed, because of the time required for this additional multiplication and division, i.e., calculation of the acceleration and output of control instructions based thereon.